Changing the IP of an website.bad for Google?

Changing the IP of an website.bad for Google? will google penalize an website for doing that?
from my experience,everytime i changed my hosting,google just there downgraded me from the search results (for exampled if i were on the first page of a keyword,after moving to new host i was placed on the page 2 or 3)for 2-3 months .Do you know something about this?
Also,using a Shared IP is bad for google ?would be better to have a dedicated IP ?

 

hmm dont think so unless you target a regional google and you change that IP to another country...

 

I don't think you will be penalized for that.

 

i changed hosting recently and did not notice any penalty

 

I dont think that would be a problem.

Shared ip is not a problem. 99% websites are on shared ip.

 

that's weird.then how come everytime i change host,i have problems with google SERPs